package com.test2;

import com.alibaba.fastjson.JSON;
import org.apache.commons.lang3.StringUtils;

import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;

public class Test5 {

    public static void main(String[] args) {
        Map<String,String> map = new HashMap<>();
        map.put("123","456");
        map.put("777","888");
        map.keySet().stream().collect(Collectors.toList());
        System.err.println(JSON.toJSONString(map));
    }

}
